Dispensers are commonly used in restaurants, factories, hospitals, and public bathrooms. These dispensers may contain fluids such as soap, anti-bacterial cleansers, disinfectants, lotions and the like, or other materials, such as powder or aerosol materials, or pre-packaged materials. Some dispensers utilize some type of manual pump actuation mechanism wherein the user pushes or pulls a lever to manually dispense a quantity of fluid into the user's hands. “Hands-free” dispensers may also be utilized wherein the user simply places their hand underneath or in front of a sensor and an electromechanical pump mechanism dispenses a metered quantity of fluid. One example of a sensor arrangement for a hands free dispenser includes an infrared light emitting diode and a light detecting photo diode that senses changes in the reflected light resulting from positioning of a user's hand under the dispenser spout.
A typical hands free dispenser requires an electrical power source, both to continually power the sensor arrangement and to power the pump mechanism in response to activation of the sensor arrangement. Internal dispenser batteries and external (AC) outlet connections are commonly used.